Robtex

Up: 2a03:4000::/31
Can't show all results, try to descend to a more specific CIDR
Down left: 2a03:4000::/33
Down right: 2a03:4000:8000::/33
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
2a03:4000::e013	A	mail.netcup.lu
2a03:4000::e013	A	ns2.netcup.de
2a03:4000::e013	A	*.netcup.de
2a03:4000::e01c	A	mail.netcup.lu
2a03:4000::e01d	PTR	ccp.netcup.net
2a03:4000:8000::fce6	PTR	dns2.dnsserver2.de
2a03:4000:8000::fce6	A	dnsserver2.de
2a03:4000:8000::fcfc	PTR	third-dns.netcup.net